Automatic draft regulator



Oct. 17, 1939. I JONES 2,176,217

AUTOMATIC DRAFT REGULATOR Filed March 24, 1937 f/C}. +2 INVENTOR.

' ao/v F JONES BY ATTORNEY.

" nemo Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE AUTOMATIC DRAFT REGULATOR tion of Michigan Application March 24,

4 Claims.

1937, Serial No. 132,675

My invention relates to draft regulators for 8 is disposed in the opening I and is designed to stove pipes or the like and more particularly to an adjustable draft regulator for the same.

One of the objects of my invention is to provide an adjustable draft regulator which may be inserted as a unit in an opening of a stove pipe or analogous pipe.

Another object of my invention is to provide a draft regulator unit which is adapted to be installed in a pipe disposed either vertically or horizontally.

A further object of my invention is to provide a draft regulator having air inlet control means that may be adjusted to operate at given draft pressures.

Still another objject of my invention is to provide a draft regulator which may be adjusted to operate at a pressure corresponding to a given draft pressure measured in inches of water.

Other objects and advantages of my invention will become apparent to those familiar with the art from the following description in conjunction with the accompanying drawing, in which:

Figure 1 is a front elevational view of my draft regulating unit;

Figure 2 is an enlarged sectional view taken along the line 2-2 of Figure 1, but showing the draft regulating unit mounted in the stem of a stove pipe T;

Figure 3 is a diagrammatic sectional view showing the draft regulator mounted in a vertically disposed stove pipe T with the air inlet control means tilted to a position which it may assume in use;

Figure 4 is a right side elevation of the structure shown in Figure 3;

Figure 5 is a view similar to Figure 3, but showing a stove pipe T in a horizontal position with the draft regulator mounted therein; and

Figure 6 is a right side elevation of the structure shown in Figure 5.

Referring to Figure 2 of the drawing, the reference numeral I indicates a conventional stove pipe T having a main pipe 2 and a branch pipe stem 2a in the open end of the latter of which is mounted my draft regulating unit. Said unit comprises an annular member generally indicated at 3 having an axially extending cylindrical portion 4, an internal flange 5, and an external flange 6. The external flange 6 is adapted to limit the extent to which the annular member 3 may be inserted into the stem opening, and the internal flange 5 defines a substantially circular air inlet opening I.

A draft regulating blade generally indicated at repose substantially vertical therein when in nonoperating position. As illustrated in Figures 1 and 2, the blade is circular and of a size to substantially fill the opening I. In order to provide 3 be bent inwardly to form aligned hump-like jour- 10 nals I I; and the flange 5 of the annular member 3 is provided with perforated projections I2 and I3 which are in alignment with said humps II. A rod member I4 is adapted to be passed through the apertured projections I2 and I3 and under- 15 neath the humps I I and thereby pivotally suspend the blade 8 in the opening I. Said rod member is located to one side of a plane passing through the middle of said blade, as shown in Fig. 1.

Furthermore, the blade 8 is concentrically ar- 20 ranged with respect to the opening I. but is spaced therefrom throughout substantially its entire periphery by an air gap I5. This spacing is maintained at all times by washers I5 mounted upon said rod member I4 and disposed between 25 the internal periphery of the flange 5 and the external periphery of the, blade 8.

A stop member I! is secured to said flange 5 by means of a fastener I8, which may be a rivet,

as shown in Figures 1 and 2, or any other suit- 0 able element. Said stop member I! has a laterally projecting portion I9 against which the surface of the blade 8 may abut when the same is tilted from its non-operating vertical position to its maximum or substantially horizontal operat- 5 ing position. A bumper plate 20 is secured to the blade 8 by means of a suitable connection II which may also be in the form of a rivet. A pad of felt 22, or some equivalent material, is secured to said bumper plate and its purpose is to elim- 4 inate noise which might otherwise occur if the bumper was allowed to strike directly against the flange 5 as the blade returns from a tilted position to the position shown in Figure 2.

Pivotal movement of the blade 8 upon the rod 45 member I4, whereby to admit air into the stem 2, -is controlled by means of an air flow regulating means generally indicated by the numeral 23. Said means is mounted directly upon the blade 8 and comprises an internally threaded 50 sleeve 24 having one end thereof secured to said blade, An adjusting screw 25 is externally threaded as indicated at 26 and is threaded into the sleeve 24. One end 21 of said adjusting screw 25 is reduced in diameter and threaded into a 55 ti e/bi metallic weight 28. The extremity of said reduced portion 21 is peened over upon said weight to maintain the same in positive assembled relation with said adjusting screw. The opposite end of said adjusting screw 25 is also reduced as indicated at 29 and an adjusting knob 30 is threadedly mounted thereupon. Said reduced end 29 is peened over upon said adjusting knob to maintain the same in non-rotative relation thereto. The adjusting screw 25 also has a portion 3| which is of a diameter slightly larger than the reduced portion 29, but smaller than the threaded portion 26, whereby a shoulder 32 is formed at the base of said reduced portion. A pointer 33 is mounted upon said reduced portion 29 and is disposed between said shoulder 32 and one face of the knob 30. Said pointer 33 is secured in non-rotatable relation to the adjust ing screw 25 by tightly jamming the same against the shoulder 32 at the time that the knob 30 is threaded upon the reduced portion 20 and prior to the peening over of the end of said reduced portion.

A body of felt or similar material 34 is disposed in a recess 35 formed in the weight 28 and lies between the outer surface of the sleeve 24 and the walls defining said recess 35. The purpose of said felt is dual. First, to prevent soot, dirt, or other foreign material from gaining access to the threads 26 and thereby interfere with the free movement of the adjusting screw 25 in the sleeve 24, as when the knob 30 is rotated to advance or retract the weight 25 relatively to the blade 8. And, second, to form what in a sense is a friction brake to maintain said weight in any desired predetermined position of adjustment with respect to the sleeve 24 and the blade 8. It will be noted from Figure 2 that the weight 28 is in the form of a truncated cone with the base portion thereof disposed nearest to the blade 8. The object of this particular shape is to distribute the metal of said weight more uniformly along its length.

Such distribution of mass being conducive to accurate control of the air admitted by the blade 8.

The screw threaded portion 26 of the adjusting screw 25 and the cooperating threads in the sleeve 24 are preferably cut on a pitch greater than standard pitch for the diameter shown. In the present case, the adjusting screw and sleeve are provided with a quadruple pitch which assures a quick axial traverse of the weight 28 relative to the blade 8 upon rotation of the adjusting knob 38. It will be clear that, a quadruple pitch is not essential and that other pitches may be used for the same purpose.

To simplify construction, the face of the blade 8 is provided with a scale or series of graduations radially arranged with respect to the axis of the adjusting screw 25 and cooperative with the pointer 33 to indicate the adjustment of the weight 28 with respect to the blade 8, and the corresponding draft pressure at which said blade will become operative. In the present disclosure, and as best illustrated in Figure 1, said graduations are marked 4, 6, 8 etc.; the same being calibrated to indicate draft pressures in hundredth parts of an inch of water. Thus, with the knob 38 adjusted to the position shown in Figure 1, the blade 8 will be operative to tilt inwardly upon the rod member It to maintain a draft pressure corresponding to a pressure of i ths of an inch of water.

It will be apparent from the foregoing, that installations.

the blade 8 may be adjusted to maintain var ious draft pressures by turning the knob 38 to move the weight 28 either closer to or farther away from the blade 8. Thus it will be obvious that, when the knob 38 is turned so as to carry the weight 28 to a position farther away from the blade 8 than that shown in Figure 2, the air pressure required to tilt said blade, or to admit air into the pipe stem 2, will be substantially greater than the air pressure required to tilt said blade when the weight is in the position now illustrated in Figure 2. This necessarily follows from the fact that, in the illustration cited, the center of mass of the weight 28 is shifted to a point farther removed from the axis of rotation of said blade.

It will also be clear from the foregoing that, as the blade 8 returns from a tilted position to the vertical position shown in Figure 2, the felt pad 22 will cushion and bring said blade quietly to rest by engagement with the internal flange 5 of the body 3. This assures silent operation of the device which is very desirable.

When the damper regulating unit disclosed herein is inserted in the stem 2* of a vertical stove pipe T, as illustrated in Figure 3, it will be apparent, that as the blade 8 swings inwardly to admit air into said stem pipe, as indicated by the arrow A, a portion of said blade will lie in the direct path of the flow of combustiongases through the main pipe 2, which in the present case is in the direction indicated by the arrow B. The flow of said combustion gases in the vertical main pipe will thus tend to further tilt the blade 8 from its predetermined position thereby admitting more air into said stem and main pipes than is consistent with the adjustment of the knob 38, and thus destroy the maintenance of the desired draft pressure. In order to overcome this possible difficulty, and to assure maintenance of the desired draft pressure, a readily detachable weight 38 is secured to the blade 8 by means of a screw 31; both being located at a point near the lower extremity of said blade. The mass of the auxiliary weight 36 is so calculated and the same is disposed such a distance from the rod member I that, as the blade 8 tends to tilt farther into the path of the combustion gases as a result of the action of said gases thereon, said auxiliary weight will counteract the effective force of said combustion gases and thereby compensate for any tendency of said gases to disturb the blade adjustment for the draft pressure desired. Thus, the weight 28 may be considered an adjustable master weight, and the weight 36 a cooperating auxiliary or compensating weight.

When the draft regulating unit is mounted in the stem of a horizontally disposed pipe T, as illustrated in Figures 5. and 6, the blade 8 is aligned edgewise with respect to the flow of combustion gases through the main pipe and in such case there is no tendency for the flow of combustion gases to disturb the desired adjustment of the blade 8. Hence, the auxiliary or compensating weight 38 is removed for such The auxiliary weight 38 adapts the draft regulating unit for use either with a vertical or horizontal stove pipe. The only adjustment required being the removal or installation of the weight 35. 7

It will be understood that various changes in the specific forms of the invention shown and described herein may be made without depart- ZOO- & HUIVHDH Y ing from the scope of the claims hereunto annexed.

I claim:

1. A draft regulator for use with a stove pipe or the like, comprising: a body member having an opening therein; a blade disposed in said opening and being of a size to substantially fill said opening and adapted to be disposed substantially vertical therein when in closed position; means pivotally connecting said blade to said body; a master weight operatively associated with said blade and disposed to one side of said pivotal means; means for adjusting said master weight comprising an internally threaded member carried by said blade, an adjusting screw having a threaded portion extending intosaid threaded member, said master weight being secured to one end of said adjusting screw, and an adjusting knob secured to the opposite end of said screw, whereby said master weight may be adjusted relatively to said blade to vary the air pressure required to tilt said blade from the vertical; a body of protective material disposed between said screw threaded member and said master weight; and an auxiliary weight operatively associated with said blade and disposed on the side of said pivotal means opposite to that of said master weight.

2. A draft regulator for use with a stove pipe or the like, comprising: a body member having an opening therein; a blade disposed in said opening and being of a size to substantially fill said opening and adapted to be disposed substantially vertical therein when in closed position; means pivotally connecting said blade to said body; and a weight operatively associated with said blade and disposed to one side of said pivotal means; means for adjusting said weight relatively to said blade, whereby to vary the air pressure required to tilt said blade from the vertical, said means comprising an internally threaded sleeve having one end thereof secured to said blade, an adjusting screw having a threaded portion extending into said threaded sleeve, said weight being secured to one end of said adjusting screw, an adjusting knob secured to the opposite end of said screw, and a body or protective material disposed between said screw threaded sleeve and said weight.

3. A draft regulator for use witha stove pipe or the like, comprising: a body member having an opening therein; a blade disposed in said opening and being of a size to substantially fill said opening and adapted to be disposed substantially vertical therein when in closed position; means pivotally connecting said blade to said body; and a weight operatively associated with said blade and disposed to one side of said pivotal means; means for adjusting said weight relatively to said blade, whereby to vary the air pressure required to tilt said blade from the vertical, said means comprising an internally threaded sleeve having one end thereof secured to said blade, an adjusting screw having a threaded portion extending into said threaded sleeve, said weight being secured to one end of said adjusting screw, an adjusting knob secured to the opposite end of said screw, and a body of protective material disposed between said screw threaded member and said master weight; and a pointer rotatable with said adjusting screw.

4. A draft regulator for use with a stove pipe or the like, comprising: a body member having an opening therein; a blade disposed in said opening and being of a size to substantially fill said opening and adapted to be disposed substantially vertical therein when in closed position; means pivotally connecting said blade to said body; and a weight operatively associated with said blade; means for adjusting said weight relatively to said blade, whereby to vary the air pressure required to tilt said blade from the vertical, said means comprising an internally threaded sleeve secured to said blade, an adjusting screw having a threaded portion extending into said threaded sleeve, said weight being secured to one end of said adjusting screw, and a body of protective material disposed between said screw threaded sleeve and said weight.

DON F. JONES. 

